Berlin 2018 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 11: Topological insulators II (joint session HL/TT)

HL 11.3: Vortrag

Montag, 12. März 2018, 15:30–15:45, A 151

Topological transport in dimer chains — •Sina Böhling¹, Georg Engelhardt¹, Gernot Schaller¹, and Gloria Platero² — ¹Institut für Theoretische Physik, Technische Universität Berlin, Berlin, Germany — ²Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid, Spain

In many fields, dimer chains have aroused great interest - not least because of the emergence of topologically protected edge states, localized to the two ends of the chain and promising lossless long-range transfer of particles. [1] Our work provides insight into properties of a dimer chain that is subject to dissipation. Applying an exact Green's function formalism applicable for any coupling strength, we investigate transport properties of a finite Su-Schrieffer-Heeger model, a paradigmatic model for a one-dimensional topological insulator, which is coupled to fermionic reservoirs at its ends.

For long chains, we observe that current and noise strongly decrease in the topologically non-trivial phase. This can be understood as a topological fingerprint, namely the occupation of edge states which are stronger coupled to the reservoirs than the conducting modes but do hardly contribute to the transmission. We show how to exploit this behavior to dissipatively prepare an edge state, while all other modes are practically unoccupied. Moreover, we discuss thermodynamic properties of the system by subjecting it to both, a potential and a thermal gradient, and discover regimes where the chain serves either as a heat engine or as a refrigerator.

[1] Bello, Creffield, Platero, Scientific Reports 6, 22562 (2016)